When Pla­to defined humans as two-legged ani­mals with­out feath­ers, I sus­pect he was only half seri­ous. Or if he was as humor­less as some sup­pose, his antag­o­nist Dio­genes the Cyn­ic cer­tain­ly picked up on the joke, point­ing out that the descrip­tion sounds pret­ty much like a plucked chick­en. The ancient back and forth illus­trates a ques­tion that has occu­pied philoso­phers for many thou­sands of years: what sep­a­rates humans from ani­mals? Is it a soul? Ratio­nal­i­ty? Tool-mak­ing? Most accounts, espe­cial­ly most mod­ern accounts, set­tle on one cru­cial difference—language. Although ani­mals can com­mu­ni­cate with each oth­er per­fect­ly well, they do so with­out this amaz­ing­ly sophis­ti­cat­ed fac­ul­ty we so often take for grant­ed.

In the ani­mat­ed video at the top, part of the BBC and Open University’s A His­to­ry of Ideas series, Gillian Ander­son, in her British rather than Amer­i­can accent, explains the well-known the­o­ry of lan­guage acqui­si­tion pro­posed by lin­guist Noam Chom­sky in the 60s. Chom­sky argued for what is known as a “uni­ver­sal gram­mar,” a kind of tem­plate in the struc­ture of the brain that allows every per­son of nor­mal abil­i­ty to learn their native lan­guage with rel­a­tive ease as a child. Chom­sky referred to these struc­tures as a “lan­guage acqui­si­tion device” that orga­nizes gram­mar and syn­tax inde­pen­dent­ly of expe­ri­ence or out­side stim­uli, of which we have pre­cious lit­tle in our for­ma­tive years. Doubt­less Chomsky’s the­o­ry would have per­suad­ed Pla­to, though prob­a­bly not the British empiri­cists of the 17th cen­tu­ry, who argued that the human mind has no innate ideas—that all of our abil­i­ties are learned.

Such was the argu­ment, much sim­pli­fied, of John Locke, physi­cian, philoso­pher, and polit­i­cal the­o­rist. In his far-rang­ing philo­soph­i­cal text An Essay Con­cern­ing Human Under­stand­ing and the more focused and digestible Some Thoughts Con­cern­ing Edu­ca­tion, Locke dis­cussed in depth his the­o­ries of human cog­ni­tion and iden­ti­ty, propos­ing not only that the mind could be writ­ten upon like a tab­u­la rasa—or “blank slate”—but that the key to human iden­ti­ty, that which makes us the same per­son from moment to moment, is mem­o­ry. We are—and are respon­si­ble for, Locke argued—what we remem­ber. Con­verse­ly, we are not respon­si­ble for what we don’t remem­ber. Locke’s the­o­ry presents us with some very thorny eth­i­cal prob­lems, which the video above most­ly avoids, but like Chomsky’s inter­ven­tion into debates about human vs. ani­mal intel­li­gence, Locke’s dis­cus­sion of the nature of human “per­son­hood” remains a time­ly con­cern, and an end­less­ly con­tentious one.

Oth­er videos in the series take on equal­ly con­tentious, and equal­ly time­ly, issues. Above, Ander­son briefly explains Karl Marx’s the­o­ry of the alien­ation of labor under an exploita­tive cap­i­tal­ist sys­tem, and below, she dis­cuss­es the role of cul­ture as a unique­ly human trait that ani­mals do not pos­sess. Each video address­es, in some small part, the ques­tion “What Makes Me Human?” and the series as a whole fol­lows quick­ly on the heels of A His­to­ry of Ideas’ pre­vi­ous set of Ander­son-nar­rat­ed ani­ma­tions on the ori­gins of the uni­verse: “How Did Every­thing Begin?”

Once again draw­ing on the skilled work of ani­ma­tor Andrew Park and scripts by inde­pen­dent philoso­pher Nigel War­bur­ton, this lat­est series of videos offers a num­ber of fas­ci­nat­ing appe­tiz­ers in the ways phi­los­o­phy, sci­ence, and reli­gion have approached life’s biggest ques­tions. Like any starter course, how­ev­er, these are but a taste of the com­plex­i­ty and rich­ness on offer in West­ern philo­soph­i­cal his­to­ry. To become a true intel­lec­tu­al gour­mand, browse our menu of free phi­los­o­phy cours­es and dig in to the work of thinkers like Chom­sky, Locke, Marx, and so many more.

Relat­ed Con­tent:

How Did Every­thing Begin?: Ani­ma­tions on the Ori­gins of the Uni­verse Nar­rat­ed by X‑Files Star Gillian Ander­son

A His­to­ry of Ideas: Ani­mat­ed Videos Explain The­o­ries of Simone de Beau­voir, Edmund Burke & Oth­er Philoso­phers

Down­load 130 Free Phi­los­o­phy Cours­es: Tools for Think­ing About Life, Death & Every­thing Between

Josh Jones is a writer and musi­cian based in Durham, NC. Fol­low him at @jdmagness